Generating Electrospray from Microchip Devices Using Electroosmotic Pumping

Dual-channel electrospray microchip.

A dual-channel electrospray microchip has been developed for electrospray ionization mass spectrometry (ESI-MS) where aqueous samples are mixed at the Taylor cone with an organic buffer. Due to the fast and effective mixing in the Taylor cone, the aqueous sample can be well ionized with a high ion intensity. The influence of geometric parameters such as the distance between the two microchannel...

Application of Charged Membranes in Electroosmotic Pumping

Rapid Biomolecule Analysis Using Two-dimensional Electrophoresis-electrospray Ionization Microchip

We demonstrate a two-dimensional (2D) separation microchip allowing capillary isoelectric focusing-capillary zone electrophoresis (cIEF-CZE) to be coupled to electrospray ionization mass spectrometry (ESI/MS). In the first dimension, separation is according to pI values (cIEF), while CZE occurs in the second dimension during mobilization towards the monolithically integrated ESI emitter. The se...

Multiple open-channel electroosmotic pumping system for microfluidic sample handling.

The development of a novel, fully integrated, miniaturized pumping system for generation of pressure-driven flow in microfluidic platforms is described. The micropump, based on electroosmotic pumping principles, has a multiple open-channel configuration consisting of hundreds of parallel, small-diameter microchannels. Specifically, pumps with microchannels of 1-6 microm in depth, 4-50 mm in len...

High flow rate per power electroosmotic pumping using low ion density solvents

We present experimental investigations of electroosmotic pumping using porous borosilicate glass and various low ion density liquids. The orking liquids were deionized water, deuterium oxide (heavy water), methanol, acetone, acetonitrile and a 1 mM sodium borate buffer as a ontrol. We measured ionic conductivity and, as a useful comparative reference, the zeta potential generated by these liqui...